Thread pull up for sewing machines



Jun 1931. R. E. PIERCE THREAD PULL-UP FOR SEWING MACHINES v I Filed Oct. 7, 1925 2 Sh ets-Shear. 1;

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June 2, 1931. R. E. PIERCi;

THREAD PULL-UP FOR SEWING MACHINES 2 Sheets-Sheet 2 NM Rn xv. :JT @N m DQN NK N WQN M N MMW N N WQ Q w \m i .3 w & N mm .T \Q B NW @n v Q. k QN *v Q h Q 1m B I N o u m N MW e um 0m m m an Rum 195.0 0:m uunr Patented June 2, 1931 umrsnifs'mrss PATENT, oFFrcE 1101mm amass; or sir. Louis; nissonai; ssronoaroxBEms Bao.. ims oo., or

ST. LQUgIS,, MISSOURI, A UORPQRZATIQN OF MISSOURI 'rnn'nnn rum: in ron snwnvo MACHINES Eppli'rratfon fil'ed endow '7, 1.92m serial No.. 635,024.

My inventionrelates to improvements in thread pull-upsvfor sewing machines, and

has for its primary object. a thread pull-up.

which. operates withthe descent of the needle-bar in; such .manner that a retrograde movement oi; the needle thread through the eye of the needle is caused during the last portion: of the descent of the needle-,vvherebya previously formed stitch is drawn up and lo tightly seated againstthe under side of the fabric.

. -'A further obiect is to construct a needle thread pull-up for sewing machines, which is adjustable so that the amount of; pull-up and the time at which it commences. can be regulated to suit various requirements of v i I 1 v i I In the drawings: 1

Fig. 1-is afront view of. a sewing machine with my device applied thereto V Fig. 2 isa topplan view of the same; Fig. 3 is an enlarged section taken on the.

line 33- of Fig. 1; i l I Fig. 4 is a top plan view-ofthecollar mounted on the needle bar which carries the thread tension; V V a Fig. 5 is a side view .of'thes-ame, looking in the direction of the arrow 5; -I

. Fig; 6 is a similar view, looking in the di rection-ofthe arrow-6; "1

Fig. 7 is a-vertical sectional view of the collar-employed;

-Fig. 8 is a side elevation ofthe same; Fig. 9' is atop planview of the stud employed in the thread tension; i Fig. 10 is a side view-,look'ng in the direction of the arrow 10;

Fig. 11 is a viewofthespring employed; Fig. 12 is a face view of the arm forming part of the pull-up; r

Fig. 13, is a side elevation of; the same;

Fig. 14 isa view ofthestudmountedin the head whichco-acts-withthe thread tension on the needle bar; i Fig. 15 is a horizontal sectionshowing the manner of securing the arm therein;

Fig. 16 is a perspective view of the arm which is mounted in the stud illustratedin Figs. 14 and 15,'and

Figure 17 is a diagrammatic view repre-v senting the relative movement of the needle;

eye,. thevarious poll-up: devices, and. the movement of thethread during movement of the needle. I

In carrying out my invention I employ a machine comprising a base 17 which has integral arm 18.. This; arm is providedwith a head 19, which is provided with suitable. bearings 20' in which the: needle liar 21 is mounted The lower end of the needle; baristapered and screw-threaded,- and slitted as;

at .22, to receive the nut 23. This nut is also provided with a tapered bore so thatv when the same is screwed up on the tapered portion 22: theneedle 24 will be tightlyjgrasped.

Extending through the arm 18 is. a shaft: 25, which is provided with a'sheave wheel 26 so that it can be placed in rotation by means ofa belt. i

Mounted on the shaft is an eccentric 2T,

which is surrounded by an eccentric strap 28. Projecting from the eccentric strap is a rod 29,Wlfl16ll in turn has secured to its upper end a bearing 30 in which a ball formed integral with the needle bar lever 31 is located. The

needle bar lever 31 is pivoted to the arm 18 at the pointindi'cated by the numeral 32. The freeend 33 of the needle bar lever is provided with links 34, which are pivotally secured. at oneiend thereto, their opposite ends being secured to a sleeve 35 mounted on the needle bar so that upon rotation of the wheel 26 the needle bar lever 31 will oscillate about'the pivot 32 and cause the needle bar 21 to reciprocate vertically.

Mounted on the arm 18 is a housing 36 which'carries an intermittently applied tension 37. This intermittent tension is operated by means of an arm 38, which arm in turn is moved upand down bymeans of'the stud 39 carried by the needle bar lever 31. 40 represents the ordinary pan or constant tension common to any sewing machine. Y

The arm 38is provided with screw threads which-work on-a screw-threaded stud 41 car ried by the housing 36 so that upon depression of the needle bar lever 31 the-arm; 38 wiube rocked and ride backward and forward on the stud 41 causing the pan- 42 to be forced toward the pan 43 and thus clamp the;

' collar to the needle bar.

thread between the ready movement.

Secured to the needle bar lever 31 is a loop 44, the purpose of which will be explained in detail later. Carried by the arm 18 is an arm having a slotted portion and a rounded portion 46. -This rounded portion extends at right angles to the portion 45 and is rounded so that there will be no sharp edges contacting with the thread. "This arm is'ad'justably secured to the arm 18 by means of a screw 47. V

The head 19 is provided in its upper surface with a circular opening in which is forced a split stud 48. This stud has openings 49 and 50 formed therethrough and at right angles to each other. One portion of the opening 50 is screw-threaded to receive the screw 51 by means of which the rod or arm 52 is held in adjusted positionfadjac'ent the needle bar. 1 s

Surrounding the upper portion of the needle bar is a collar 53 which is provided with a screw-threaded boss 54 inwhich islocated a screw 55 for the purposeof securing the pans and hold it against isa passage-way 64 which'leads from one side of the stud and permits: the insertion of the needle thread without; the trouble of threading it through the opening. V

"Surrounding the stud 58 is a sleeve 65,

' which is provided with a head (36. This head is provided with a tapered face 67 (see Figs. 7 and 8) which is for preventing sharp edges fromcontacting with the thread.

The stud 58 is also provided witha head 68, between whichand the head 66 of the sleeve the coilspring 69 is interposed. In this manner I obtain a slight constant tension on the needle thread suflicient to prevent a double loop from forming when the machine is in operation and by this means also the needle thread is retained in the bore 63. The machine is also provided with a bar 70 which has an opening 71 formed therein, through which the thread is first passed, and which serves to guide it to the pan tension 40.

I have not shown the mechanism which operates the under thread, as this forms no essential part, of my 'device,-because I may use either the looper or a shuttle in conjunc tion with my thread pull up and achieve the same results. It is to be understood, however,

that my device is to be operated in conjunc- The collar is also 7 7 tion with a sewing machine employing two threads. 4

In threading my device, the thread is first passed through the opening 71 formed in the bar 70, then between the pan or constant tension 40, then between the intermittent tension. It is then threaded through the loop 44, then brought down through the opening 63 in the stud 58 and finally through the eye of the needle.

The material to be'sewed is placed under thepresser-foot and the machine started in the usual manner. Upon the descent of the needle, the needle will-first penetrate the goods and the concatenation of the threads will take place." Upon further descent of the needle and the downward movement of the needle bar and needle bar lever, the inter-' mittent lockwillbdoperated, clamping the thread between the pans 42 and 43 and pre-- venting any further thread being drawn from the source of supply. This locking takes place before the needle has reached itslowest point of descent; l i

A further downward movementof thencedlebar and its operating lever will-cause the stud 58 and the eye 44 to pass below the top of the arms 52 and 46. By so doingit vwill be necessary to supply additional thread from the head-19. {The stud 48 may'alsobe raised or lowered if found necessary-,so as to get more or lessfpull onthe'needle thread.

However, for'ordinary adjustments I have found that the screw 47 answers all purposes.

While I have shown and described aparticular kind of thread look, I do not desire to limit myself thereto, the only essential-feature being that the thread lock be placedadjacent the pan iorconstant'tension ori the source of supply, sothat when the pull-up occurs the thread will be locked between the point of pull-up and thesource of supply, and therefore-a retrograde movement of the needle threadithrough the eye of the needle occurs during a portion of'the needles descent. Havingfullydescribed'my invention, what I claim is:-+-" 1 1. A device of'the-class describedicomprising a sewing machine having an arm,a

mounted in -s'aid-'head, a needle bar lever mounted on said arm for operating said needle bar, a needle carried by said bar, a slotted adjustable arm mounted on the sewing machine arm, an adjustable arm carried by the head, means carried by the needle bar lever and the needle bar and co-acting with the arms carried by the head and the sewing machine arm for imparting a pull-up on the needle thread during the last portion of the needle descent, and means carried by the sewing machine arm for clamping and arresting the feed of needle thread from a source of supply while the pull-up is applied.

2. In a sewing machine having an arm, a head, a needle bar, a needle, a needle bar operating lever, and an intermittent thread lock for arresting the feed of needle thread from and adjacent a source of supply, an adjustable slotted arm located on said arm, an adjustable bar carried by said head and co-acting with means located on the needle bar and needle bar operating lever whereby a pulling up movement of the needle thread between the needle and the intermittent thread lock is produced during the descent of the needle and while the thread is locked, and means for adjusting the means 011 the arm and head whereby the amount of pull-up can be regulated.

3. A device of the class described com prising in c mbination with a sewing machinehead, an arm integral therewith and the operating mechanism carried thereby, a constant tension, and means carried by the arm and adjacent the constant tension for intermittently arresting the feed of needle thread during a portion of the needle descent, a pivoted lever carried by the arm of said machine for operating a needle bar, a slotted adjustable arm carried by the arm of said machine above the pivoted lever and extending beyond said lever, an arm carried by the head of the machine, means carried by the needle bar and by its operating lever and co-acting with the slotted adjustable arm carried by the arm of the machine and the arm carried by the head oi the machine during a portion of the needle descent for producing a retrograde movement of the needle thread through the eye of the needle while the needle thread feed is arrested.

a. A device of the class described, the combination with a sewing machine having an arm, a head integral with said arm, a needle bar mounted in said head, a needle bar lever pivotally mounted on said arm, and a link for operatively connecting said needle bar and needle bar lever, of a constant thread tension carried by said arm adjacent its rear end, an intermittent tension mounted on the upper face of said arm in advance of the constant tension, an arm pivotally carried by said intermittent tension and adapted to be moved up and down by said needle bar lever for operating said intermittent tension,

a loop carried by the needle bar lever in ad- Vance of the intermittent tension, an ad ustable slot-ted L shaped arm carried by the sewing machine arm and adjacent the head, a stud carried by the sewing machine head and projecting upward therefrom, an adjustable arm projecting horizontally from said stud, and a spring-actuated constant tension secured to said needle bar at its upper end.

In testimony whereof I have aflixed my signature.

ROBERT E. PIERCE. 

